If you've ever wondered why there are sometimes baffling winners at the Academy Awards, a Hollywood director's blistering assessment of this year's nominees indicates how quirky and personal the voting can be.

The anonymous member of the Academy of Motion Picture Arts and Sciences, talking to The Hollywood Reporter as he filled out his ballot, said he was voting for veteran Emmanuelle Riva for best actress because she might not live through Oscar night, described Argo as "a whole lot of nothing" and called Django Unchained "Quentin Tarantino masturbating for three hours".

His colourful insider views, which dismissed many leading contenders at the 85th Oscars, raise the prospect of upsets on Monday (Australian time).

While Argo, Ben Affleck's political thriller, is widely expected to claim the best picture Oscar after a string of wins during lead-up awards, the director refused to vote for it for best adapted screenplay, describing it as "a whole lot of nothing; it's a very engaging story but with nothing particularly clever in the writing".

He also rejected Argo for best picture ("I don't want it to win because I don't think it deserves to win and am annoyed that it is on track to win for the wrong reasons") but was far from flattering about every other nominee except his preferred winner – Zero Dark Thirty.

The director wrote off Amour ("I'm just pissed off at that film"), Beasts of the Southern Wild ("a movie that I just didn't understand"), Les Miserables ("the most disappointing film in many years"), Silver Linings Playbook ("just a 'blah' film") and Django Unchained ("a fun movie but it’s basically just Quentin Tarantino masturbating for almost three hours").

He described Life of Pi as "unique" and said it held his attention "until its irritating ending" and was happy with Lincoln winning the best picture Oscar even though "it's a bore but it's Spielberg, it's well-meaning and it's important".

While Jennifer Lawrence is favourite to win best actress for Silver Linings Playbook, the Hollywood director said she lost him with a Saturday Night Live appearance that he thought was "mean-spirited and shows a lack of maturity on her part".

"For the first hour of The Impossible, you can't imagine how Naomi Watts cannot win but her character basically becomes a person who is exclusively struggling and who disappears for large chunks of the film so I can't vote for her," he said, adding that he would not support young Quvenzhane Wallis from Beasts of the Southern Wild either because "I don't vote for anyone whose name I can't pronounce".

He settled on Riva, who turns 86 on the day of the Oscars, ahead of Jessica Chastain.

"I didn't like Amour but I think Riva was extraordinary in it. Chastain was just fantastic in Zero Dark Thirty – she is the major star of tomorrow and probably has another 10 Oscar nominations in her future. Meanwhile, Emmanuelle Riva may not even live through Oscar night."

But the director made his dislike of Amour clear when he dismissed it in the best original screenplay category.

"It's just a woman dying and there's no real story and it made me feel like shit. There's only so much diaper-changing that I can tolerate."

The director, whose identity will no doubt be the subject of speculation in Hollywood, agreed with the bookies that Anne Hathaway will win best supporting actress for Les Miserables but stuck the knife into her Australian co-stars in assessing her performance.

"She makes you cry and ... I find her charming," he said.

"Sometimes it's one scene that wins it for you. Not just anybody can come in and kill one song; there are many songs that Hugh Jackman and Russell Crowe should have killed and, in fact, they killed them literally".

The director matched candour with crassness when it came to voting for best live-action short.

"Curfew is the least depressing of five films guaranteed to prevent you from getting laid, as I personally learned," he said.